Natural Disasters

Indo-Gangetic Plain, Meghalaya will need to use flood protection for 1,000 years: DTE analysis

DTE analysed the need for flood protection measures in India in response to a study on the subject published in Nature

By Pulaha Roy
Published: Monday 04 October 2021

The Indo-Gangetic Plain (excluding West Bengal and Assam) and Meghalaya are most susceptible to future floods in India and need to employ flood protection for the next 875-1,000 years, an analysis by Down To Earth (DTE) has found.

The analysis drew from data released in a recent study published in the Nature journal titled Residual flood damage under intensive adaptation.

The Indo-Gangetic Plain (including the Indus and Ganga basins) here includes the states and Union territories of Jammu, Kashmir and Ladakh, Punjab, Uttar Pradesh and Bihar.

Authors of the study calculated the extent of flood protection that countries would need to employ in terms of years.

They estimated the global cost of employing adaptive flood measures — depending on local economic scenarios and cost adaptation measures — by trying to quantify the cost of residual flood damage (RFD).

RFD ‘refers to unavoidable increases in flood damage even under an adaptation strategy based on feasible adaptation costs’. Adaptation strategy — in the context of floods — implies infrastructural measures that have been employed to mitigate the risks posed by floods.

But while a high RFD means higher adaptive costs, the benefits definitely outweigh the costs.

According to the study’s estimate, RFD in South Asia is estimated to be around four million while adaptive costs around three million.

But the benefits from the measures employed attune to over 50 million under the RCP8.5/SSP5 scenario. On a global scale, the benefits run into $74 billion.

The role of RFD and the correlation that exists between the two variables has remained limited in scope in the past. This, even as past studies have estimated the cost of adaptive measures.

The study, through the prism of cost and benefit, tries to quantify the cost of adaptive measures which need to be employed by estimating expected annual damage (EAD).

RFD — which is part of the total EAD outlay — is calculated by subtracting past EAD (1970 - 2000) and future EAD estimates (set to 1,000 years which is the maximum protection level as shown in the graphic).

RFD (as part of the gross domestic product) remains high in eastern China, the northern parts of India and the central regions of the African continent. This is according to the analysis carried out by the researchers.

Riverine floods in India have become synonymous with economic losses. According to data from Central Water Commission, the total flood-related losses in the country were estimated to be over Rs 37 lakh crore from 1953 to 2017.

Subscribe to Daily Newsletter :

Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.